Question: I have extreme hair loss and very brittle fingernails that split and crack. They also have deep ridges on the surface of them. Should I be tested for thyroid problems?

Dr. Hibberd's answer:

Yes, definitely. All these symptoms are associated with under active thyroid disorders, and you should have your thyroid evaluated. Deep horizontal nail ridges should be signals to your doctor that a disease may be the underlying cause. Vertical ridging is much less of a concern.

Horizontal ridges may be caused by trauma, infection, a skin disease, malnutrition, hypocalcemia, chemotherapy, infection, drugs, or other health problems. A single blood test and physical evaluation should provide all the information your doctor will need to diagnose you correctly.